Storms have killed 16 in the US and temperatures are set to reach lows not seen for a generation

New York state was facing nearly two feet of snow this weekend after storms in the north-eastern US on Friday claimed the lives of at least 16 people. With temperatures as low as -23C, forecasters issued dire warnings of what lies in store.

One meteorologist, Ryan Maue of Weather Bell, called the system of cold air approaching the midwest a “polar vortex”. “All the ingredients are there for a near-record or historic cold outbreak,” he said. “If you’re under 40, you’ve not seen this stuff before.”

The temperature was predicted to fall as low as -35C in parts of Minnesota, with wind chill potentially making that feel like -56C. In a region accustomed to brutally cold weather, however, the Green Bay Packers’ NFL wild-card playoff game against the San Francisco 49ers at Lambeau Field is expected to go ahead today, as the coldest NFL game ever played.

Forecasters said it would be -19C at the evening kickoff and -22C by the fourth quarter. Fans, who bought the remaining 40,000 tickets last week after the NFL threatened to prohibit local TV from airing the game if the team were unable to sell out, were warned to take extra precautions, such as dressing in layers and sipping warm drinks.

Minnesota’s governor Mark Dayton ordered schools closed across the state for the first time in 17 years. In North Dakota, “life-threatening wind chills” were forecast until Tuesday morning.

Maue added that, although the cold spell approaching the midwest would last for only a few days, “it raises the chances for future cold” across the country. The NFL is watching such forecasts closely, as it has scheduled Super Bowl XLVIII to be played on 2 February at MetLife Stadium in New Jersey, the outdoors venue shared by the New York Jets and the New York Giants. Contingency plans are in place to play the showpiece game, which is usually staged at warm-weather venues or in domed stadiums, on 1 or 3 February if necessary.

“Right now for the winter we will have had two significant shots of major Arctic air and we’re only through the first week of January,” said Maue. “And we had a pretty cold December.”

The cold blast will also affect parts of the east coast, which is still clearing up after Friday’s storms. Sally Johnson, a meteorologist at the National Weather Service in Sioux Falls, said: “This one happens to be really big and it’s going to dive deep into the continental US. And all that cold air is going to come with it.”

Nearly two feet of snow fell on some north-eastern areas on Thursday night and into Friday, causing widespread road and flight delays, closing schools on the second day back after Christmas and leading the governors of New York and New Jersey to declare states of emergency.

Cities from Washington DC to Portland, Maine, were affected, although the heaviest snow fell north of Boston. Nearly 18 inches fell there and in parts of New York state. There was 6 innches of snow in Central Park, New York.

Nearly 3,500 flights were cancelled on Friday across the US; 12,394 were delayed. On the roads, deaths were reported in Michigan, Kentucky, Indiana and Illinois. A road gritter was killed in Philadelphia when a pile of rock salt fell on the machine he was operating. and authorities said a 71-year-old New York state woman suffering from Alzheimer’s disease died after leaving her rural home.

Authorities rescued a number of people from accidents caused by the ice and snow. On Friday a man was rescued after falling through the ice at Ramapo Lake in New Jersey. A police dive rescue team pulled 34-year-old Guncel Karadogan to safety and resuscitated him. He was taken to a local hospital. In Monmouth, in the same state, fire officials said the three people were rescued after the Shrewsbury River flooded on Friday morning.

In New York City, the snow provided an immediate test for the new mayor, Bill De Blasio, who took office on New Year’s Day. De Blasio, who in 2010 was one of the leading critics of his predecessor, Michael Bloomberg, for allegedly prioritizing the clearing of Manhattan over the other four boroughs, was photographed shovelling snow in front of his Brooklyn home.

Asked about the snow-shoveling effort made by his 16-year-old son Dante, who achieved a certain fame in the election campaign and who the mayor’s wife, Chirlane McCray, said would be sent out to shovel snow, De Blasio said: “I give Dante an A for effort and a D for punctuality.”

New York City transport was affected by the storm, with some highways shut overnight and commuter services running on weekend or reduced schedules, but by Saturday morning services were largely back to normal. Over the Hudson river in New Jersey, the governor, Chris Christie, closed state offices and courthouses and ordered non-essential workers to stay at home.

Authorities warned the public to be ready for continuing low temperatures. The governor of Massachusetts, Deval Patrick, said: “Temperatures are expected to be extremely low, and dangerously so. These are dangerous conditions.”

New York City’s department of homeless services doubled patrols seeking those who needed shelter and streamlined its check-in process.